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Processors, speakers, amplifiers and wiring

The purpose of this article is to detail a practical and
cost-effective upgrade path for cinemas, including multiplexes,
that wish to install 70mm, for example as part of a
Premiere Screen project.

The starting point is a single standard 5.1 cinema processor,
with future 10-channel capability to allow for, for example,
9-Channel soundtracks.

To this is added a DTS player / processor and reader for DTS-70
soundtracks, with an option for magnetic playback for archival
70mm material. An audio switcher with capability for up to 10
channels is inserted into the signal path to permit reproduction
of both formats.

It should be noted that, in a desired context of revived,
limited 70mm distribution from
65mm originals, a
multiplex cinema could easily forego the archival 70mm playback
option, thus further saving on the cost of magnetic head
assemblies, preamps and the switcher.

Bi-amplification is a requirement for an
upgrade of this kind. Fortunately, many cinemas today have bi-amplified
sound systems installed for 35mm and digital presentations. In very
large theatres, tri-amplification should be actively considered.

Loudspeakers should also be mounted in an infinite baffle (baffle wall)
behind the screen in order to improve dialogue clarity and bass
response.

The Workshop is grateful to Ben Wales, UK, for his assistance with this
article, and to Peter Fearn,
Service Engineer, DTS Europe for additional information supplied.

Note that this article does not imply endorsement by the manufacturers
concerned for the particular equipment choices and configurations
presented herein.